W O 3 ∕ metal thin-film bilayered structures as optical recording materials

Abstract

Interface reactions in WO 3 / metal thin-film bilayered structures were examined for applications to optical recording materials. Decreases in the reflectance of the structures caused by temperature elevation were observed and were attributed to (i) coloration of the WO 3 layers, and (ii) decreases in the reflectance of the metal layers resulting from redox reactions between the WO 3 and the metals. The reflectance spectra of the structures before temperature elevation showed moderate wavelength dependence over a wide range, from the visible to the near infrared. Decreases in the reflectance due to temperature elevation occurred over a wide wavelength range. Examination of the WO 3 / Al-Ti bilayered structures as potential optical disk memories revealed that the redox reactions occurred within submicrosecond time periods during irradiation with the recording laser.The results indicate that these structures possess promising properties for applications to optical recording materials that can be used over a wide wavelength range.

Nanostructured Tungsten Oxide – Properties, Synthesis, and Applications

“…Driven by the need for high‐density and reversible information storage, optical recording is an advanced technology, which has seen application in everyday life 195. The initial exploration of WO x for this field used a combination of photochromic and electrochromic effects to record digital images 1.…”

Characterization of WO3Thin Films Grown on Silicon by HFMOD

“…WO 3 thin films can be prepared by various deposition techniques such as thermal evaporation [3,7], spray pyrolysis [8], sputtering [9], pulsed laser ablation [4], sol-gel coating [10], and chemical vapour deposition [11]. The purpose of this work is to characterize the WO 3 layers deposited by hot filament metal oxide deposition (HFMOD) technique, which uses a metallic filament heated in a rarefied oxygen atmosphere [12].…”

Confocal spectromicroscopy of amorphous and nanocrystalline tungsten oxide films

“…The use of a reversible photoredox reaction under two-wavelength laser excitation of tungsten oxide in air was proposed for optical memory media in [7,8]. The reflectance change upon heat treatment of WO 3 /metal thin-film bilayered structures was studied in [9]. Rewritable electrically selective multilayered optical recording disk, based on the electrochromic behavior of WO 3 , was suggested in [10].…”

“…However, other compounds are subject of continuous investigation for optical recording media [4]. In particular, tungsten oxide, well known for its electrochromic properties [6], was studied in [7][8][9][10][11]. The use of a reversible photoredox reaction under two-wavelength laser excitation of tungsten oxide in air was proposed for optical memory media in [7,8].…”